Brain and Body Systems Flashcards
draw the flow diagram of CNS<->PNS with notes for each section
see notes
what is the purpose of the Peripheral NS?
the implement the CNS’ connection with the body/wider world
when is the parasympathetic NS active?
during rest and digest when in relaxed state
when is sympathetic nervous system active?
during fight or flight/aroused state when there’s a stressor
draw a diagram of the BBB and it’s elements
see notes- the image B
why does the brain need so much
vasculature?
the brain has high metabolic needs, using about 20% of cardiac output, despite being 2% of body weight.
Because it has very little storage ability glucose and oxygen need to be delivered as and when it’s needed through a dense capillary network
what is the downside of the dense vasculature/constant blood supplied required by the brain?
it makes it vulnerable if there’s any interruption, which can quickly was local/wider injury and dysfunction
what is neurovascular coupling
whereby neuronal activation triggers increased BF to an area
Neurovascular unit ~
BBB
define BBB
an interconnected system of neurons, astrocytes, pericytes, vascular cells (endothelial cells)
what are hormones
signalling molecules produced by endocrine organs throughout the body and transported around the body via vascular system. Essential for development, physiology and behaviour by regulating systems to maintain desired state
what has overall control of the endocrine system?
the brain (with feedback architecture)
what’s the basic flow chart of endocrine/hormone?
hypothalamus-> pituitary -> hormones secreted to effect other glands/systems
name 3 differences between hormones and neurotransmitters:
- NTs are faster acting, hormones slower
- NTs travel shorter distances (along neural networks), whereas hormones can travel throughout the body (via circulatory system)
- NTs act in the shorter term, whereas hormones have longer term effects
- NTs have digital actions (on/off), whereas Hormones have analogue (continually variable)
- NTs tend to have more targeted action, whereas hormones as more diffuse
(overall hormones are able to reach parts of the body NTs can’t access, working through different mechanisms that complement CNS/PNS
Overview of hormones and BBB
hormones travel in the blood, so BBB cells have receptors for them in order for hormones from body to trigger neural changes. Hormones produced in the brain can also cross the BBB often to go on to target endocrine receptors in the body. Some BBB cells are autocrine and some paracrine
overall, where does the hypothalamus receive input from?
cerebral cortex (including somatosensory cortex), amygdala, hippocampus and visceral sensory input
overall, where does the hypothalamus output to?
visceral and somatic motor neurons, neuroendocrine and behavioural pathways
how does the hypothalamus connect/communicate with anterior pituitary?
via short BVs (sending releasing hormones for pituitary to release into blood
how does the hypothalamus connect/communicate with posterior pituitary?
through neural connections
what diseases are implicated in the connection between brain disease and neurovascular function?
diabetes, NT disturbances, stroke, epilepsy
what did a review by Kulshreshthra (2019) show?
that CVD risk factors, such as hypertension and cigarette smoking and positively associated with cognitive decline (showing link between CV health and brain function)
what did Barnes (2015) review show?
exercise both reduces CVD risk and is protective of cognitive function (indicating link between cardiovascular health and brain health)
what is the proposed mechanism by which cardiovascular health is impacting brain health?
many studies have shown changes in circuit function (functional connectivity)
because there is a lack of effective treatments for CNS diseases involving cognitive decline/dementia, it’s important to…
look at preventative lifestyle factors to avoid onset
what are the strongest evidenced factors shown to increase the risk of both cognitive decline and dementia?
- TBI
- mid-life obesity
- hypertension
- current smoking cigarettes
- diabetes
what’s the strongest evidenced factors that reduce the risk of cognitive decline and dementia?
- greater number of years of formal education
- physical activity
what does the immune system do?
senses environmental change in body and co-ordinates a response, including cellular, biochemical, physiological/behaviour changes. It self-regulates and remembers
what are the 3 levels of the immune system?
- Anatomical/Physiological barriers (counts as innate immunity)
- Innate immunity
- adaptive immunity
give 2 examples of anatomical/physiological barriers:
2 from:
- skin
- ciliary clearance
- low stomach pH
- lysozyme in tears and saliva
what is innate and adaptive immunity further divided into?
cellular and humoral
give 3 cells of innate immunity:
3 from:
- eosinophils
- macrophage
- mast cells
- dendritic cells
- neutrophils
- natural killer cells
give 2 examples of aspects of innate humoral immunity:
2 from:
- complement system
- mannose binding lectin
- antimicrobial peptides
- LPS binding protein
- c-reactive protein